Have you been misinformed about aluminum boilers?

Patterson-Kelley, one of our most trusted brands of boilers, has published a blog post on the myths and misinformation surrounding aluminum boilers and how they are actually beneficial.

Aluminum is one of the best heat exchanger materials and Patterson-Kelley wants to prove it, joining the ongoing industry debate between aluminum and stainless steel boilers.  We are sharing their article here but you can see the original on their site as well –  “Breaking the Stigma on Aluminum Boilers”.

Changing the Perception of Aluminum Commercial Boilers

The commercial heating industry has faced an ongoing debate on the benefits of stainless steel heat exchangers versus aluminum heat exchangers. The process of choosing a new boiler has become confusing for both building owners and engineers.

The amount of conflicting information has led many boiler manufacturers to pick a side, and the perception of aluminum heat exchanger boilers has been misconstrued in the process. Yet, there is no clear evidence or proof that either material is superior to the other.

The heat exchanger is the part of the boiler that uses heat generated from fuel combustion to raise the temperature of heating water. Both aluminum and stainless steel condensing boilers achieve high efficiency by condensing water vapor in the exhaust gases and recovering its latent heat, which would otherwise be wasted. With condensing flue gases comes highly acidic water, which can adversely affect the fired heating surface. During the heating process, impurities and contaminants, like chloride and pH levels, can directly affect the water chemistry in the boiler. Regardless of the heat exchanger material (aluminum or stainless steel), EVERY boiler should be introduced and maintained with the appropriate air and water quality to prevent corrosion and scaling.

In this blog we will focus on the benefits of owning an aluminum commercial boiler, with the intention of breaking the stigma created by the ongoing debate. Keep in mind that Patterson-Kelley offers both, aluminum and stainless steel options, which places our team in an unbiased position.

Why Choose an Aluminum Commercial Boiler?

  1. High thermal conductivity
    • According to the Kent’s Mechanical Engineers’ Handbook, the thermal conductivity of pure metals is inversely proportional to absolute temperature. Thermal conductivity is an important factor when selecting a heating unit because it defines the velocity at which heat passes through the material. Aluminum is considered a high purity metal and it is 8x better at thermal conduction than stainless steel. Even though aluminum heat exchangers require thicker walls in a commercial boiler application, it is also lighter in weight and it has a high strength to weight ratio. The thickness of the heat exchanger does not negate the heat transfer advantages.
  2. Large Waterways
    • Large surface areas and water channels can deliver lower hydraulic resistance. This means that the water moves slowly through the heat exchanger which allows the returning water temperatures to absorb potential heat, resulting in higher efficiency. A cast aluminum heat exchanger design with large waterways also makes the system more tolerant to variable system conditions, including flow rate settings.
  3. Corrosion Resistance
    • In contact with fresh water, the corrosion rate of aluminum is relatively high. However, after a few weeks, aluminum features a protective layer of aluminum oxide film, which significantly reduces the corrosion rate as well as the risk of oxidation. This layer is highly resistant to corrosion caused by acidity.
  4. Longevity & Manufacturing Flexibility
    • The thickness of the heat exchanger walls can greatly improve the longevity of unit. Aluminum is also known for being flexible, versatile and economical. It provides casting capabilities, allowing extended heating surface areas with limited volume without compromising heat transfer rates.

Both MACH Engines

Aluminum and stainless steel are both great heat exchanger materials and have excellent properties. The uniqueness of the commercial boilers is not only based on the material of the heat exchanger, but how the components work together. The key factors to monitor in a commercial boiler application, regardless of the heat exchanger material, include operation, water quality, air and fuel. These components will affect the life expectancy and maintenance requirements of the heating unit(s).

If you have any further questions on the benefits of aluminum vs. stainless steel boilers, please give us a call at 800-355-7061.

 

Do you take care of your boilers, with a regular maintenance program? If not, you should. Boilers, like cars or any other mechanical devices, are subject to wear and tear. They need adequate maintenance, to ensure that they don’t break down because if they do, it’s guaranteed NOT to be at a convenient time to repair it. Waiting until something breaks down before repairing and maintaining it, always ends up costing you far more money, unhappy residents, higher labor rates, etc. because it’s usually during peak service demand, or in the middle of the night, or on a weekend. Usually, you end up in scramble mode trying to fix a problem that could have been avoided with regular care. Providing regular maintenance programs to your customers, is also a good way to build long-lasting customer relationships and add a consistent revenue stream for your business.

Annual maintenance and monthly water quality checks can prevent premature malfunctions and potential boiler breakdowns caused by poor water quality, leaks or water pressure. Any boiler’s functionality can be easily compromised and impact energy efficiency which creates a large bill for your customers.

So, what are some best practices to keep boilers operating in peak condition? Here are 8 annual maintenance steps you can take to help maintain energy efficiency and extend the life of your boiler.

  1. Replace all parts affected by wear and tear, every year!

Our PK annual maintenance kit includes all parts that need to be replaced, including gaskets to re-seal the combustion inspection covers that you need to remove in order to clean the fire-side. Right now, we’re offering a limited time 20% discount on our Patterson-Kelley Boiler Annual Maintenance Kits (part #BP-0000-0345) until September 15th. 2018. Order yours today.

  1. Inspect the fireside of the heat exchanger

After 2,500 hours of operation, or at least once a year, you should inspect the fire-side of the heat exchanger. You can access the fireside by removing the inspection covers. Any fireside fouling should be removed by using clean out tools and water washing the fireside surface. A thin coat of mineral oil can be used on an aluminum boiler to help minimize potential fouling in between annual maintenance checks. Verify that no debris came loose and fell to the bottom, potentially clogging the air path.

  1. Remove the burner, thoroughly wash and clean the mesh

This should be done even if the burner appears to be clean. After washing the burner; reinstall it and use the fan test option to blow dry the burner. DO NOT fire the burner while wet.

  1. Replace old igniter, flame rod and gaskets

These parts are included in your maintenance kit. It is important that you DO NOT reuse old gaskets.

  1. Select the righT Water Treatment to Prevent Scale

Water side scale is equivalent to having a thin film of insulation between the furnace gases and boiler water. It can drop a boiler’s efficiency by as much as 12% – 21%.

  1. Re-start the equipment and adjust combustion using a calibrated analyzer

A water tube manometer will be necessary to check for proper draft readings.

  1. Inspect electrical connection for corrosion

Condensation can cause corrosion on the electrical connections of a boiler. Check for broken or cracked fusers and replace anything that looks questionable, then test the unit. It is also important to ensure that the electrical connections are tight.

  1. Clean the condensate trap

Once again, the condensate produced by condensing natural gas boilers is corrosive. The condensate trap must be cleaned annually and inspected for potential leaks.

You can also download this checklist from Patterson-Kelley on how to design the system to ease annual boiler maintenance.

Mechanical Equipment is your local Patterson-Kelley representative, and you can call us anytime if you have questions, concerns or would like to order a Patterson-Kelley Boiler Annual Maintenance Kit. Call before September 15th to get 20% off!  800-355-7061.

Patterson-Kelley recently published a blog post on innovation in boiler controls that we thought would be of interest to you. They are one of our most trusted lines of heat transfer equipment like boilers and water heaters. As you will see in the blog post, Patterson-Kelley is definitely committed to making boiler control technology one of the most impressive features of your heating systems. Read on!

The Evolution of Boiler Controls

The technological innovation of boiler systems has drastically enhanced how users interact with their boilers. The industry continues to improve safety and efficiency standards to fit the game changing environment. Today, users seek features that influence the return on their investment. These notable features include increased energy efficiency, great zone controls and low operational costs; all of which can be achieved by selecting the right boiler control technology.

Boiler control systems have evolved through the years, reducing energy waste and providing the user with greater control over their equipment. Innovation helps to facilitate day to day processes, and allows boilers to better respond to the genuine requirements for comfort heat and hot water demand.

Prevent Boiler Short-Cycling

We all want our heating system to increase cost savings and reduce carbon emissions. However, the issue of boiler short-cycling is the primary reason for boiler inefficiency, generating high operational costs for building owners. Boiler short-cycling occurs when the system fires only to recover its standing heat losses, without genuine comfort heat or hot water demand.

In a previous era, “time delay” devices were introduced to attempt to prevent short-cycling. This device keeps the boiler from firing on fixed time delays. However, it does not take heat or hot water demand into consideration, limiting the end user’s ability to realize cost saving energy reductions.

The introduction of building management systems(BMS) and building optimization positively affected the heating industry by increasing efficiency and providing the end user with more control over their system. But once again these controls have resulted in the implementation of technology that can interfere with existing control strategies, compromising the comfort levels of a building.

Today, we use a modern and intelligent boiler load optimization control. The computer-based control allows for continuous monitoring of both flow and returning temperatures in real time. The control consists of both hardware and software, and engineers have even found a way to integrate the use of internet protocols.

The Patterson-Kelley Solution

The Patterson-Kelley NURO® control system constantly analyzes the boilers outlet temperature and compares it to the current comfort heat setpoint. This enables the control to identify and prevent the boiler from short-cycling. When the outlet temperature drops below the setpoint, the NURO® commands the boiler to increase its firing rate, and as it approaches the comfort heat set point, the control will command the boiler to decrease its firing rate. Both the Comfort Heat Wizard and the Domestic Hot Water Wizard in the NURO®, allow the end user to easily set up and tune the comfort parameter for optimal performance. The control also allows for remote monitoring through a desktop or mobile device, with the NURO® Connect App. Who better knows how to control the boilers than the boiler manufacturer themselves.

The success of this approach led Patterson-Kelley to engineer a NURO® Conversion Kit, which allows current MACH® boiler owners to convert their control to the latest technology.

We’d be happy to talk with you and answer any questions on the Patterson-Kelley Boiler Control options for your next project. Give us a call at 800-355-7061.

This post originally appeared here

Don’t wait for it to get cold! Mechanical Equipment is offering a limited time 20% discount on our Patterson-Kelley Boiler Annual Maintenance Kits (part #BP-0000-0345). This special offer will be applied to maintenance kits orders starting July 10, 2018 through September 30, 2018.

As we approach the fall maintenance season, the importance of annual maintenance will help ensure optimal performance of your Patterson-Kelley Boilers and frankly, all of your equipment. Annual maintenance work provides your company with additional service revenue, gives you an opportunity to get in front of your customers again, and keeps them happy with superior service.

Orders of 15 or less maintenance kits will usually ship within 5-7 days. For orders, greater than 15, please call us to get the estimated ship date.

To order or learn more about our Patterson-Kelley Annual Maintenance Kits, just contact our office at 800-355-7061.

Patterson-Kelley is one of our most trusted lines of heat transfer equipment like boilers and water heaters. They recently published this article on boiler turndown rates that we thought you would find it of interest.

 

Operate at Peak Efficiency

Thermal efficiency is simply the chemical energy added to the boiler divided by the energy added to the boiler water.  As more energy is transferred from the hot gas into the boiler water, the thermal efficiency increases and the temperature of the hot gas decreases.

Almost all boilers are tuned to add excess air, which ensures ideal combustion of the fuel for proper air-fuel mixing. The excess air can also prevent the burner from overheating by “pushing” the combustion flames off the burner.

When energy from the hot gasses is transferred to the boiler water, the gas temperature dips below the dew point, which causes vapor to become liquid. The energy released from the conversion is picked up by the boiler water and results in a significant boost in efficiency. Every pound of water converted into liquid adds approximately 1000 BTUs to the boiler water. However, dry flue losses and loss of vapor can result in energy loss.

Energy loss can be readily calculated if the amount of CO2 and O2 in the flue gas and the stack temperature is known.

With the evolution of boiler technology, manufacturers have found a way to offer units with multiple firing rates, and units that can modulate seamlessly between fixed low fire rates and fixed high fire rates. The fixed fire rates are defined as the boiler turndown capacities, and modulation is accomplished by reducing the air and gas flow into the boiler.

The benefit of this modulation is threefold; it reduces cycle losses, it reduces the wear on the components, and it can potentially lead to higher thermal efficiencies.

Impact of Turndown

This begs the fundamental question – wouldn’t a boiler with extreme turndowns be much more efficient than one with 5:1 turndown?  The answer to that is NO!

To achieve high turndowns, the boilers are tuned to deliver greater amounts of excess air at low firing rates to keep the burner from overheating. The additional excess air will significantly reduce the dew point of the water in the flue gas and alter the losses in the dry gas. To illustrate this effect, the example used in Figure A is updated to reflect a 20:1 turn down where the O2 is set to 11% (corresponding to a CO2 of 5.6% and 97% excess air).  The results are highlighted in Figure B below.

Note that the dew point has been lowered from 130.6° F to 117° F  and the boiler is no longer in the condensing range.  This represents a 3.7% DECREASE in overall efficiency and this is just the beginning of the bad news! 

When excess air well above 50% is used in the boiler, it impacts the stability of the combustion flame which can lead to excessive flame failures, nuisance trips and cycle losses.

The Analysis

Realistic boiler modulation rates have helped improve the overall boiler system efficiency from reduced cycle losses and increased thermal effi­ciencies. Extreme turndown produces the opposite effect. Boil­er plant designs must factor in actual (not extrap­olated) boiler efficiencies through the firing range of the equipment and matching the expected plant loads with the right boiler size selections.

Interested in learning more about Patterson-Kelley boilers or how turndown rates affect efficiency? Give us a call at 800-355-7061 and we’d be happy to help.

Mechanical Equipment is offering a 15% discount on our Patterson-Kelley Annual Maintenance Kits (part #BP-0000-0345 ). This special offer will be applied to maintenance kits orders starting October 16th, 2017 through October 31st, 2017.

As we approach winter, the importance of annual maintenance will help ensure optimal performance of your Patterson-Kelley Boilers and frankly, all of your equipment. Annual maintenance work provides your company with additional service revenue, gives you an opportunity to get in front of your customers again, and keeps them happy with superior service.

To learn more about our Patterson-Kelley Annual Maintenance Kits, just contact Dean in our office at 800-355-7061.